I agree - having looked at crossover design and how involved it is, I think I'd have more chance learning rocket science!
I like the idea of the 1.5 way so along with a few other things, will have plenty to experiment with. As long as these surrounds do the job I'll be happy. Is there a formula for working out what capacitor will give a particular crossover point for this application, or is it much like a single order crossover, and will an on-line crossover calc do the job (or the one in WinISD beta)?
Cheers
Gary
I like the idea of the 1.5 way so along with a few other things, will have plenty to experiment with. As long as these surrounds do the job I'll be happy. Is there a formula for working out what capacitor will give a particular crossover point for this application, or is it much like a single order crossover, and will an on-line crossover calc do the job (or the one in WinISD beta)?
Cheers
Gary
IME a shallow depth cabinet is not a big deal in practice. I've made shallow TL's less deep than the Jordan TL with no issues. Spheres OTOH - now there's a problem...
+1, this app combined with the driver specs 'screams' a 'pancake' MLTL alignment to me with the driver at extreme top and vent down at the floor or just off the floor, down firing.
GM
Normally, I'd include enough design dims to build one using your driver's specs, but currently don't have access to the HD with all my programs, etc., so hoping Scott or others will take up the slack for me till I can get another older XP Pro/SP2 desktop computer that will allow me to run the HD's existing operating system to replace this ancient 'beater' Win7 laptop on loan.
Anyway, since you only need to vent it to allow a lower XO point, inverting the speaker to vent at the top to open up aisle space is fine since it will be many dB down at tuning [Fb], so just part of the surround's ambient background noise.
Frankly, if one uses multiple subs to average out room modes where one is up either at the ceiling or at least up a wall at an odd harmonic, then venting all of the speakers at the ceiling is a viable option.
That, or do as one crusty old EE/DIYer I knew back in the '60s did way before anybody ever considered multiple speaker/sub systems for HIFI apps AFAIK, which was to make a TL cardboard tube speaker that stopped short of being floor/ceiling height with some having a little 'FR' driver at each end and some just at one end and others offset at odd harmonics of its length, then located in the corners and around the room at odd harmonics to create a believable surround sound that to mine and the few others he associated with sounded way more 'real' than the quadraphonic systems that debuted ~5 years later.
Would it still sound 'real' today? I seriously doubt it now that DSP has advanced enough to almost completely fool us, but as others have proved, it's still a viable option for systems up to ~250 Hz, maybe even higher in some apps, something I hope to explore before I become too senile/croak.
GM
Anyway, since you only need to vent it to allow a lower XO point, inverting the speaker to vent at the top to open up aisle space is fine since it will be many dB down at tuning [Fb], so just part of the surround's ambient background noise.
Frankly, if one uses multiple subs to average out room modes where one is up either at the ceiling or at least up a wall at an odd harmonic, then venting all of the speakers at the ceiling is a viable option.
That, or do as one crusty old EE/DIYer I knew back in the '60s did way before anybody ever considered multiple speaker/sub systems for HIFI apps AFAIK, which was to make a TL cardboard tube speaker that stopped short of being floor/ceiling height with some having a little 'FR' driver at each end and some just at one end and others offset at odd harmonics of its length, then located in the corners and around the room at odd harmonics to create a believable surround sound that to mine and the few others he associated with sounded way more 'real' than the quadraphonic systems that debuted ~5 years later.
Would it still sound 'real' today? I seriously doubt it now that DSP has advanced enough to almost completely fool us, but as others have proved, it's still a viable option for systems up to ~250 Hz, maybe even higher in some apps, something I hope to explore before I become too senile/croak.
GM
hi GM,
Thanks for the offer despite being unable to do that right now, it's more than I would have expected
If it wasn't for the need to have the surrounds closer to ear height I would have some coaxials all round, about 6 feet or so from the floor and that would have been just fine, plus I could have the same drivers in the ceiling too. I'm hoping this route will work well though considering the ears are only going to be around 2 to 7 feet from the drivers.
Your friends idea of FRs in tubes and the way he had them laid out seems a brilliant idea. I wonder if it would still work despite what modern tech can offer these days.
I'm approaching the senile/croaking phase of life too, and I'm up to my ears in other stuff so I'm trying to get myself a head start with this so I can get it all up and running without having to research it too much when I'm building the room.
Cheers
Gary
Thanks for the offer despite being unable to do that right now, it's more than I would have expected
If it wasn't for the need to have the surrounds closer to ear height I would have some coaxials all round, about 6 feet or so from the floor and that would have been just fine, plus I could have the same drivers in the ceiling too. I'm hoping this route will work well though considering the ears are only going to be around 2 to 7 feet from the drivers.
Your friends idea of FRs in tubes and the way he had them laid out seems a brilliant idea. I wonder if it would still work despite what modern tech can offer these days.
I'm approaching the senile/croaking phase of life too, and I'm up to my ears in other stuff so I'm trying to get myself a head start with this so I can get it all up and running without having to research it too much when I'm building the room.
Cheers
Gary
Chances are you've seen this already, but FWIW, Dolby has some information on Atmos speaker setup on their website.
Atmos Speakers
The first thing that is apparent is that implementing the system correctly apparently involves either ceiling speakers or up-firing surrounds and mains, though it is supposed to be compatible with standard 5.1 and 7.1 setups.
It's interesting to note that Dolby uses KEF Uni-Q coaxial drivers for their Atmos speakers. Apparently they also value the importance of a point source for this system.
It would be possible to DIY something similar, as Uni-Q drivers are occasionally available for sale. However it would involve crossovers....
FR drivers are probably the best bet here. If you simply choose a reasonably appropriate driver, likely someone will help you with the cabinets. Off the top of my head, I'd suggest Alpairs or Jordans -- if they are within budget. A Tangband, Visaton et al would be good choices if you want to go cheaper.
BTW it's not a great idea to mix and match too many different drivers. Perhaps try to use the same ones for center and surround channels.
Atmos Speakers
The first thing that is apparent is that implementing the system correctly apparently involves either ceiling speakers or up-firing surrounds and mains, though it is supposed to be compatible with standard 5.1 and 7.1 setups.
It's interesting to note that Dolby uses KEF Uni-Q coaxial drivers for their Atmos speakers. Apparently they also value the importance of a point source for this system.
It would be possible to DIY something similar, as Uni-Q drivers are occasionally available for sale. However it would involve crossovers....
FR drivers are probably the best bet here. If you simply choose a reasonably appropriate driver, likely someone will help you with the cabinets. Off the top of my head, I'd suggest Alpairs or Jordans -- if they are within budget. A Tangband, Visaton et al would be good choices if you want to go cheaper.
BTW it's not a great idea to mix and match too many different drivers. Perhaps try to use the same ones for center and surround channels.
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Hi Greg,
The 5.1 or 7.1 remains much the same, but due to the addition of ceiling speakers the surrounds need to be lower to increase separation, hence my problem
I was going to use some Eminence 10CX coaxials for all surround and ceiling speakers (I have one ready to go), but they are too deep. Initially they were going to be higher up on the walls above the seats and not low enough to encroach in the aisle space which is narrow to start with.
That's what lead me to thinking about another point source which was a full range driver that could fit into a shallow box.
Other than the LCRs, I'd like to try and keep all speakers the same, though the rears (if they get used) will have to fire as far as the fronts to a second row, so could be an issue.
Tangband and Visaton are more my price range although currently I have some Wharfdale 4" FR drivers that were used in the modus cubes so I thought I could experiment with those for effectively no cost to me now.
I did model a box using WinISD beta but wasn't sure if that was the way to go with these or if there was a better way to use them. Are they suitable for a vented enclosure? I believe one of the T&S parameters can tell you this can't it?
Gary
The 5.1 or 7.1 remains much the same, but due to the addition of ceiling speakers the surrounds need to be lower to increase separation, hence my problem
I was going to use some Eminence 10CX coaxials for all surround and ceiling speakers (I have one ready to go), but they are too deep. Initially they were going to be higher up on the walls above the seats and not low enough to encroach in the aisle space which is narrow to start with.
That's what lead me to thinking about another point source which was a full range driver that could fit into a shallow box.
Other than the LCRs, I'd like to try and keep all speakers the same, though the rears (if they get used) will have to fire as far as the fronts to a second row, so could be an issue.
Tangband and Visaton are more my price range although currently I have some Wharfdale 4" FR drivers that were used in the modus cubes so I thought I could experiment with those for effectively no cost to me now.
I did model a box using WinISD beta but wasn't sure if that was the way to go with these or if there was a better way to use them. Are they suitable for a vented enclosure? I believe one of the T&S parameters can tell you this can't it?
Gary
Late to the party, but what are the room's other 2 dimensions? A few years back I tried running a 2 channel only system in a room approx 8.5ft wide by 22ft long, and even with acoustic treatment on walls and corners, it was hard to get not only clean bass, but any width of virtual sound stage.
I can't help but wonder if a total of the minimum of 7 speaker channels that I understand the Atmos system to entail* would result in cacophony without substantial acoustic treatment in such a narrow space.
* anywhere from 5.1.2 for the "essential" home Atmos set up, to 7.1.4 to 9.1.2 "particularly suited for larger rooms"
then again, it took me long enough to go for simple 5.1 and only 42" screen - while watching with me last night, my wife asked if I thought I wanted a larger screen - I know if I go shopping for one the merry go round will never stop
edit: that said, I'd be inclined to agree with Greg B - for the bandwidth of information and SP levels at which however many surround channels you implement, a small FR driver makes a lot of sense - something like an Alpair, Fostex or TangBand 4" or so would make for a very compact install, and this is one of the few cases where an in-wall or ceiling installation can make sense, if you don't mid the mess and patch-up required. .
I can't help but wonder if a total of the minimum of 7 speaker channels that I understand the Atmos system to entail* would result in cacophony without substantial acoustic treatment in such a narrow space.
* anywhere from 5.1.2 for the "essential" home Atmos set up, to 7.1.4 to 9.1.2 "particularly suited for larger rooms"
then again, it took me long enough to go for simple 5.1 and only 42" screen - while watching with me last night, my wife asked if I thought I wanted a larger screen - I know if I go shopping for one the merry go round will never stop
edit: that said, I'd be inclined to agree with Greg B - for the bandwidth of information and SP levels at which however many surround channels you implement, a small FR driver makes a lot of sense - something like an Alpair, Fostex or TangBand 4" or so would make for a very compact install, and this is one of the few cases where an in-wall or ceiling installation can make sense, if you don't mid the mess and patch-up required. .
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Hi Chris,
Most HT rooms need treatment of some sort and in my last room I did some basic deadening below ear height which made a huge difference. This time I might try to be more scientific and do some measuring.
The room is 9ft wide by 17 feet long by 8.5 feet high.
The room will need complete refurbishment anyway, so it's going to be a mess from the start, including potentially a new ceiling. Anything I do should be an improvement...
Thanks for the conformation of going for FR speakers. I've found a few alternatives but unfortunately, no measurements other than T&S (unlike Tangband an Fostex), so they could sound crap, but just being for surround duties mean they don't have to be hifi quality. I might try a couple just to see once I've got my Umik mic out of its box and have learnt how to Measure stuff. As it is, 4" FRs will have the least impact on the width and that's the main reason for going that route.
Cheers
Gary
Most HT rooms need treatment of some sort and in my last room I did some basic deadening below ear height which made a huge difference. This time I might try to be more scientific and do some measuring.
The room is 9ft wide by 17 feet long by 8.5 feet high.
The room will need complete refurbishment anyway, so it's going to be a mess from the start, including potentially a new ceiling. Anything I do should be an improvement...
Thanks for the conformation of going for FR speakers. I've found a few alternatives but unfortunately, no measurements other than T&S (unlike Tangband an Fostex), so they could sound crap, but just being for surround duties mean they don't have to be hifi quality. I might try a couple just to see once I've got my Umik mic out of its box and have learnt how to Measure stuff. As it is, 4" FRs will have the least impact on the width and that's the main reason for going that route.
Cheers
Gary
While some folks might enjoy the learning curve and process of measuring drivers, rooms, etc towards the goal of speaker design / room treatment wouldn't any Atmos receiver / processor come with mike and on-board calibration process to simplify the speaker set up as much as possible? Of course, they don't prescribe acoustic treatment protocols - yet
I know for sure that even when using the active cross-over / bi-amp option for front mains, my latest Onkyo was much easier to set up than the network configuration for screen share operation of a headless MacMini as music server. Just plug in the mike, and let 'er rip.
I know for sure that even when using the active cross-over / bi-amp option for front mains, my latest Onkyo was much easier to set up than the network configuration for screen share operation of a headless MacMini as music server. Just plug in the mike, and let 'er rip.
Most do seem to have an eq system, with Audessey XT32 seeming to get the best reviews, so I would like to think that would be my final saviour should all else fail!
I might try and dig out the Wharfedale 4" drivers and see what they sound like in a simple baffle and maybe even build a vented box as per WinISD just to see how they compare. Getting the time these days is the problem, but it would be nice to know what they'd sound like before the room gets under way (could be some time yet, but I can't stop my curiosity in the mean time).
Gary
I might try and dig out the Wharfedale 4" drivers and see what they sound like in a simple baffle and maybe even build a vented box as per WinISD just to see how they compare. Getting the time these days is the problem, but it would be nice to know what they'd sound like before the room gets under way (could be some time yet, but I can't stop my curiosity in the mean time).
Gary
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